Ron Rosenfeld wrote in message . ..

A friend corroded the cylinders on his Cardinal from continuous
heating in just one winter. The water/acid boiled off the oil and
condensed in the cylinders on the bottom side. I understand Tanis
says that won't happen since they also have cylinder heat, but I'd be
more than a little scared of it still happening. If nothing else
minimize the preheat as much as convenient.

Lycomings especially need preheat to keep the cam from scoring. The
problem isn't bearings, it is all the expensive-to-repair surfaces
like cylinders and camshaft/lifter surfaces that depend on a fog of
oil for lubrication. Unfortunately if you push your luck on a cold
start, the fog isn't developed for some time as the oil that blows
over the relief valve has little access to the heat of the engine.
After it warms up and sprays from the bearings etc, it does.